Over 30 years have passed since the Chernobyl disaster devastated the city of Pripyat, Ukraine, and left its citizens fleeing for their lives. At the time it was difficult to imagine that anything positive could come of such horror. However, over the years and in the absence of humans, an incredible story of land reclamation by a number of native animals has fascinated both scientists and the public alike. The area has since become a ‘radio-ecological laboratory’, where scientists have studied the effects of radiation on these animals since the turn of the millennium.

A new study from the University of Georgia has used a remote-camera scent-station survey to reveal the abundance of wildlife within the Chernobyl Exclusion Zone (CEZ). The team observed a total of 14 mammal species altogether, with ample visits from 4 species in particular – grey wolves (Canis lupus), raccoon dogs (Nyctereutes procyonoides), Eurasian boars (Sus scrofa) and red foxes (Vulpes vulpes). The study built on previous work from 2015, which counted animal tracks to determine that populations were thriving within the CEZ.

“The earlier study shed light on the status of wildlife populations in the CEZ, but we still needed to back that up”, said James Beasley, an assistant professor with UGA’s Savannah River Ecology Laboratory and the senior author of the paper. “For this study we deployed cameras in a systematic way across the entire Belarus section of the CEZ and captured photographic evidence – strong evidence – because these are pictures that everyone can see.”

Racoon dog within the Chernobyl Exclusion Zone. Credit: TREE Project

The contemporary research involved setting up remote cameras at 94 different sites, using a fatty acid scent to attract the animals. The team documented every species captured on camera, but paid particular focus to carnivores. They explained that they decided to focus on carnivores due to their significance in the food chain.

“Carnivores are often in higher trophic levels of ecosystem food webs, so they are susceptible to bioaccumulation of contaminants”, Webster said. “Few studies in Chernobyl have investigated effects of contamination level on populations of species in high trophic levels.”

Bioaccumulation refers to the accumulation of chemicals – sometimes toxic – in an organism. Although all animals are vulnerable, top-level predators are more likely to receive contamination, either by ingesting contaminated prey or receiving it directly from affected soil, water or air.

“We didn’t find any evidence to support the idea that populations are suppressed in highly contaminated areas,” Beasley said. “What we did find was these animals were more likely to be found in areas of preferred habitat that have the things they need – food and water.”

Eurasian lynx in the Chernobyl Exclusion Zone. Credit: TREE Project

Eurasian lynx (Lynx lynx) in the Chernobyl Exclusion Zone. Credit: TREE Project

The study of the animals of the exclusion zone has been rife with contention, with scientists unable to agree on whether the mammal population has fallen or grown since the area has been void of human activity. Although some claim that the CEZ has become an unlikely sanctuary to some of Europe’s rarest species, others argue that there is little data on the prevalence of radiation-related defects in individual animals.

“Our results suggest that robust populations of numerous mammals now occur throughout much of the CEZ, including areas with [high] radiation levels,” the study concludes.

reference

Sarah C Webster, Michael E Byrne, Stacey L Lance, Cara N Love, Thomas G Hinton, Dmitry Shamovich, James C Beasley. Where the wild things are: influence of radiation on the distribution of four mammalian species within the Chernobyl Exclusion Zone. Frontiers in Ecology and the Environment, 2016; DOI: 10.1002/fee.1227

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